Hey Wayne great question, I don't have direct experience with either of the specific models you are asking about but I have looked through a few armasight Zeus scopes and own a pulsar trail scope (xq38, and a Reap-IR). IMHO, if your only concern is the magnification issue I would consider a couple things. One, you have already pointed out- having to zoom in for shots, especially the longer ones. The Zeus would win hands down in that category, I think.
One thing that people don't seem to realize though is that at night when it's dark, you have to rely on your equipment much more than your eyes, so if you don't have a back up thermal scanner or some type of night vision for navigation, then the lower magnification/wider field of view of the the pulsar xp50 would be beneficial, depending on the type of hunting that you do. Do you sit in a stand, walk and stalk, drive and stalk? Are you mostly hunting one location at a time or are you constantly on the move checking multiple spots? Are the specificic locations you hunt mostly thicker cover or wide open land?
If most of your hunting is stationary and you have time to scan often and aren't moving around a whole lot then the higher magnification/clearer view of the armasight Zeus would probably have more advantages there.
If you are constantly moving around scanning through some thicker vegetation then the lower magnification of the pulsar might help u find creatures that u would have otherwise not noticed more than u may realize now.
All that being said I'll add a "couple" things.
The stated magnification on the pulsar scopes doesn't seem to match up with what I have actually seen looking through the lenses on them. I think what pulsar claims on their magnification is lower than what the eye actually sees compared to other scopes. When I compare my trail xq38 ("2.1x ") and my Reap-ir ("2.5x") (my brother in law also has a trail xq50 [2.7x] so I have a decent amount of experience looking through that one as well), my trail xq38 actually has slightly more zoom/ a more narrow field of view than my Reap IR even though, based on their stated native magnifications, you would assume otherwise. So, IMO, the base magnification claims aren't always exactly completely accurate according to what our eyes see. I will also say that though I don't have direct experience with the armasight/flir Zeus 3x 75mm or the pulsar trail xp50 (1.6x), I would assume the Zeus still has a good bit more native magnification comparably to the pulsar trail xp50. I would also assume the Zeus has a bit sharper image than the pulsar even if their magnification/field of views were the same-- apples to apples, but again I haven't done any direct comparisons between them.
All that being said, I think the pulsars have a better price point value wise. I also think it's worth considering things like battery life, video recording capability (if you're into that sort of thing), the factory mount each scope comes with vs aftermarket mount options, the scope having multiple preset zeroes (the ability to mount the scope to multiple guns without rezeroing provided you have a good mount that will return to zero when remounted), wifi- being able to sync the view through your scope's lens to your phone or iPad while scanning/hunting, multiple color palettes etc.
The Pulsar trail scopes come with a rechargeable battery that lasts about 7 hours and take up no extra space on the scope. It also has an internal video recorder. It also has the wifi to sync with your smart phone. I'm not sure about the new models shipping out but supposedly they come with a new mount that holds zero really well and isn't as big and bulky as the older original ones. I do know that u can buy a D-loc mount for them from ultimate night vision that is lightweight, small, fast and ergonomical and does an awesome job at returning to zero if u ever wanted to mount it to 3 different rifles and zero it to them and have the option of using the scope on on 3 different guns without rezeroing.
I'm not sure what mount the standard Zeus comes with. I assume ultimate night vision also makes a D-loc mount for them and I'm pretty sure the Zeus Pro line comes with a really good mount from a well known manufacturer like ADM (I think but could be wrong), but I believe the Zeus scopes don't come with multiple preset zero options. One problem with the Zeus that I've heard is that the battery life on them sucks, especially in cold weather. I'm not sure if that's only on some defective models or if that's on all units. Pretty sure the current Zeus also doesn't have the option to use wifi to sync the view through the lens to your phone. You would also have to buy a separate video recorder for the scope if u wanted to record your hunts. I do think the Zeus has the option of multiple color palettes. I think both scopes have adjustable focus.
For me, I had to spend an extra $275 for a separate video recorder for my Reap-IR, and a separate external battery pack/cord to run the scope all night (another $150). I woulda had to do the same thing with the Zeus. The pulsar already came with both of these options and more.
With the pulsar, I had to spend an extra $275 on the Dloc mount so I could zero it to 3 different guns and feel confident that I could remove and return it to any of those three guns and that it would still hold and return to zero. I don't know if the Armasight will do that with the factory mount or not.
So, All that being said, if you're mostly hunting from a stationary position with the same gun for a couple/few hours per night hunting at longer ranges often like shooting a coyote at distance and not interested in extra features I would probably go with the Zeus. If you're constantly on the move hunting all night, and want to drive and scan and walk and scan and often hunting areas that have closer shots/thick cover, shooting a sounders of hogs at 50 yards and want to record your hunts, and want to use the scope on multiple guns easily, I'd go with the Pulsar.
I'm sure Brian Schaffer will chime in soon enough with lots of great info as well. He has much more direct experience with the Zeus 3x 75mm and will probably make some great points for its advantages.
I hope this helps and sorry for rambling a bit!!
